3D PIC-MCC simulations of discharge inception around a sharp anode in nitrogen/oxygen mixtures

Research output: Contribution to journalArticleAcademicpeer-review

63 Citations (Scopus)

Abstract

We investigate how photoionization, electron avalanches and space charge affect the inception of nanosecond pulsed discharges. Simulations are performed with a 3D PIC-MCC (particle-in-cell, Monte Carlo collision) model with adaptive mesh refinement for the field solver. This model, whose source code is available online, is described in the first part of the paper. Then we present simulation results in a needle-to-plane geometry, using different nitrogen/oxygen mixtures at atmospheric pressure. In these mixtures non-local photoionization is important for the discharge growth. The typical length scale for this process depends on the oxygen concentration. With 0.2% oxygen the discharges grow quite irregularly, due to the limited supply of free electrons around them. With 2% or more oxygen the development is much smoother. An almost spherical ionized region can form around the electrode tip, which increases in size with the electrode voltage. Eventually this inception cloud destabilizes into streamer channels. In our simulations, discharge velocities are almost independent of the oxygen concentration. We discuss the physical mechanisms behind these phenomena and compare our simulations with experimental observations.

Original languageEnglish
Article number044005
Number of pages13
JournalPlasma Sources Science and Technology
Volume25
Issue number4
DOIs
Publication statusPublished - 14 Jun 2016

Keywords

  • 3D
  • discharge
  • inception
  • nanosecond
  • photoionization
  • PIC-MCC

Fingerprint

Dive into the research topics of '3D PIC-MCC simulations of discharge inception around a sharp anode in nitrogen/oxygen mixtures'. Together they form a unique fingerprint.

Cite this